2011 Panasonic VT30 Black Levels Rise after all!

Don't know why people bother complaining about this despite always knowing its going to happen.

Don't want it. Don't buy a Panasonic. Problem solved.

Interesting chart. Do we know what causes the levels to drop at first, then rise again?

I believe a sample size of 1 is insufficient to draw any meaningfull conclusions.

jeff

I think I remember D-Nice mentioning that the 2011s might still have a rise in them, but that it wouldn't be nearly as significant as previous models.

xrox has posted on the subject before but what it looks like is that both Panasonic and Samsung (LG's probably doing it too) have implemented in their driving schemes a mechanism for maintaining and balancing performance (black level, pixel stabilty, lifetime, brightness, etc) as time goes on and the panel ages. It's pretty clear that whatever driving settings are appropriate when the set is brand new would not be appropriate when the set has many thousand hours on it due if nothing else to the phosphors becoming less efficient.

So some variation in performance over time is to be expected because the adjustment scheme seems to be a fixed program rather than some actual feedback based closed loop control. The 2010 implementation apparently was somewhat hamfisted or overly aggresive, 2011 seems better but clearly still shows some variability in performance.

All that said, I still maintain that a single data point isn't a good sample.

jeff

I'll be curious to see how Panasonic responds to the report.

I also noticed that Dave K has the Contrast set to 87 which I think is relatively high. I wonder if the rise is a function of average screen brightness over time?

It started around .006 when new.

How is this a raise?

the charts from David K
https://docs.google.com/spreadsheet/...3c&output=html

Well what that chart shows me is that if you buy a TV based on just black level than the 3 Panasonics are better than the 2 Samsungs even IF they rise

I'd just like to know if it eventually levels off and maintains.

Also, I'd love to hear if the 65" panels behave in the same manner.

I have a P65S2 with 3,300 hours on it. The picture looks amazing to me. It also does to my friends. Of the 100's of people that have watched it over the last 18 months not one has ever commented "Oh my, those black levels sure have risen" or "those blacks aren't good"

Is the P65S2 immune to rising blacks? Is noticing rising blacks only an affliction of videophiles? Is it only really noticeable once you have measured it with a meter and then you can't stop noticing it and thinking about it? Does anyone really think the blacks are not really that black except for videophiles?

I think that the black and rising black issue that so few people notice or care about (and I am talking about all Panasonic purchasers, not just the videophiles out there) will likely never be addressed by Panasonic And that is because Panasonic is directing their resources towards 99.999% of the market, not the other .001%, as any prudent company would.

My guess is, yes. It seems like it's just very difficult to hold a black level that low for a very long period of time for Panasonic.

I agree. The hysteria is amusing. Of course, it's not NEARLY as nuts as the "bezel" crisis's LOL!

ONE data point rise, on
ONE model and
ONE sample

with an end result of about the same as it started.

The Samsungs are the REAL story..

Up and STAYING there over time.

Indeed.

And to add the Samsungs actually still measure the same as they did initially. It's just David won't post the black levels numbers after he corrected the brightness control.

His tests are a "how far do the sets drift from their initial calibration". Obviously the Samsungs brightness (black) drifts up probably from the TV trying to self adjust a bit. But a small compensation with the brightness control puts the blacks right back to where they started at .0065 ish.

Lots of room for errors in the testing and as you pointed out the sample size is way to small. And really the deltas between ALL of the panels says to me the blacks are very good anyway (minus the LG).

I read that and still purchased a VT30/65-->

HH

At the point this occur you are so burned in on the tv it´s a non issue. That is the nice thing of owning a tv for a longer period. It only get better even though it measure worse

As I said in the owners thread (sorry to double post - but it seems relevent here as well)

Look at the data and sample size.

So the VT30 tested has a black level at 2000 hours (0.0068) that is pretty much the same as it had out of the box (0.0062).

What is the accuracy of the measurement tool and measuring environment? Is it within 0.0006?

It sounds like 0.001 - 0.002 difference (an order of magnitude higher) is hard to see. The author says "The difference in absolute depth of black was quite subtle between the VT30 (0.0061 fL) and the Samsung [PND8000] (0.0071), not to mention the GT30 (0.0082)..."

This sounds a little like this article 'WSTS strips value from Q1 chip market' which says quote 'The net result has been to strip about 91.1 million in value out of the first quarter's sales figures, which is now listed by WSTS at $75.675 billion, compared with the previous figure of $75.766 billion.' http://www.eetimes.com/electronics-n...Q1-chip-market

Sometimes you have to put the absolute numbers in perspective......

The odds are unless Katzmaier took a whole mess of readings over a couple of days that the difference between new and now is well within the margin of error and Undecided's conclusion is correct.

That gap is so small, the instruments so barely designed to measure such a subtle difference, that it's very hard to really believe some programmatic change has occurred. More significantly, even if it had, good luck detecting it with your naked eye.

that report is confusing.
first says starts a .0045 now .0068.
Then something about starts at .006?
I was paying attention to the VT30 mll as reported by the calibrators. seems .004 was average when new.
even some saying .0035.
so if it is now .0068, that is SIGNIFICANT.
Maybe Dave K can straighten this out.

That's probably the reality of it. The closer I looked and the graph and numbers, seems like a non-issue.

blacks rise again but in smaller incremants and over a longer period of time

people need to stop rationalizing and just accept it...and yes I own the 55" VT30

The VT30 looks to be skyrocketing. Is he done with measurements or will he continue at least another 4k hours?

Nevermind:

Unfortunately I strongly suspect that the VT is not done rising. Just a hunch.

This don't seem sooo baaad....

cnet
For a little more perspective, it's worth remembering that a difference of two thousandths of a footlambert is pretty tough to discern. In a side-by-side comparison in the VT30 review I said: "The difference in absolute depth of black was quite subtle between the VT30 (0.0061 fL) and the Samsung [PND8000] (0.0071), not to mention the GT30 (0.0082)..."

cnet
For the record I consider its improved color a worthwhile trade-off for the slight loss in black-level performance.

I think the white level measurements are
even more interesting. Of the panasonics,
the light output is GT>VT>>ST. Admittedly
this is with the ST in cinema mode. However,
DK seems to suggest that the other modes
don't perform well/accurate enough to include in
the test?

My 42" ST30 calibrated either just as good or slightly better than Cinema in Custom mode with mid panel brightness and at 2000 hours. Only trade off was a .010fl in Custom and a .009fl in Cinema...which I think are about average for the smaller screen sizes...

Similar experience as mfrey0118. Chad B recently calibrated my 65ST30 and it did extremely well...especially in Custom at 48fl.

Just more continuous blather to deflect from the fact that Panasonic STILL has a better black level than the competition.

I suppose, but it's still not that impressive considering panasonic can't reach the level of some 4 year old tvs that shall not be named.